Now that I've moved all STE-related announcements to a separate Twitter account (@wdeditor) instead of mixing them up with my own personal messages, Artimonier does not match any existing user name mentioned to me that he can't use STE because he has a free account here at Wikidot.

I'd like to crush this right here and now as I am sure many other people falsely believe this as well.

Free account holders can also use the Wikidot API!

However, the process is a bit longer for you, most likely as an anti-spammer measure (spammers are unlikely to pay to become Pro users, so they get API keys instantly).